Louvered grill

ABSTRACT

The invention relates to a louvered grille for an air conduction housing, comprising a plurality of louvers which are spaced apart from one another to form air passage openings, wherein the louvers extend in the widthwise direction of the louvered grille and have an upper louver face that is directed to the exterior and inclined transversely with respect to the vertical direction of the louvered grille. For better IP protection of such a louvered grille, according to the invention the upper louver face of at least some of the louvers has a convex curvature in at least some areas of the louvers, both in the widthwise direction of the louvered grill and in the vertical direction of the louvered grille.

The invention relates to a louvered grille for an air conduction housing, comprising a plurality of louvers which are spaced apart from one another to form air passage openings, wherein the louvers extend in the widthwise direction of the louvered grille and have an upper louver face that is directed to the exterior and inclined transversely with respect to the vertical direction of the louvered grille.

Louvered grilles of this type are known from the prior art. Louvers are used which extend inclined in the widthwise direction of the louvered grille between two supporting bars. The louvered grilles serve to cover air conduction housings which are inserted into an opening of a switchgear cabinet wall of a switchgear cabinet. The louvered grilles cover the air conduction housing to the exterior to offer a certain mechanical access protection. Rain water may be drained off along the inclined surface of the louvers, so that it cannot reach the interior of the switchgear cabinet. The so-called IP classification determines protection of the louvered grille. To this end, the resistivity encountered by the louvered grille against intruding objects mechanically on the one hand and against intruding humidity on the other hand, is stated. If a particularly high protection is required, it is necessary that the louvered grille resists to the impact of a steam cleaner acting from the exterior.

It is the object of the invention to create a louvered grille of the type mentioned in the introductory by which high IP protection, in particular in view of the resistance against intruding humidity, may be realized.

This object is achieved in that the upper louver face of at least some of the louvers has a convex curvature in at least some areas thereof, both in the widthwise direction of the louvered grille and in the vertical direction of the louvered grille. In this way, a dual convexly curved surface of the louver results. That convexity results in that an impinging water jet of a steam cleaner is atomized at the louver, so that it loses its kinetic energy. Thus, the strength of the steam jet is broken, and the risk of intruding water is considerably reduced.

According to a preferred variant of the invention, it may be provided that the louvers are strip-shaped and, starting from a center portion thereof towards the longitudinal ends, slope in the vertical direction. In this way, a curved louver shape is provided, wherein water draining off the upper louver face is directed laterally to the edges of the louver. Thus, an improved draining off of water from the louver and an increased IP protection may be realized.

A further preferred variant of the invention is such that the louvers have, at a lower louver face facing away from the upper louver face, a concave curvature in at least some areas thereof. That concave geometry forms a labyrinth-like flow barrier for water.

In order to block intruding water which for example acts from a steam cleaner through passage openings formed between the louvers, a conceivable alternative of the invention provides that the louvers comprise a barrier wall at the lower louver face thereof, which barrier wall is angled with respect to the lower louver face and extends towards a rear side of the louvered grille. At this barrier wall, intruding water encounters resistance. It has proven to be particularly advantageous that the barrier wall, starting from the center portion of the louvered grille, has a larger dimension in direction of the depth of the louvered grille than at the longitudinal ends thereof. Thus, the barrier wall has a larger wall height in the center portion of the louvered grille than in the lateral regions. This measure improves, on the one hand, resistivity against intruding spray water, on the other hand, the louver is effectively stiffened in its center portion, i.e. where the highest tensions within the material may be expected when mechanically stressed.

The louvers have an upper edge extending in the widthwise direction of the louvered grille and a lower edge, also extending in the widthwise direction of the louvered grille. It is preferred that these two edges are embodied having curved contours, wherein the radii of the two curved contours are different from one another. Thereby, an improved removal of the water jet is supported. Additionally, the lower curved edge offers a dripping water edge to reliably conduct away flowing water drops without carrying away water droplets formed at the dripping edge by the air jet passing through the air passage openings.

If it is provided that a filter mat is provided in the region of the rear face of the louvers which is spaced apart from the louvers, then an expansion space is created behind the louvers. Now, if a water jet penetrates between the louvers through the air passage openings, it is kept bundled between the louvers and then reaches the expansion space. Here, it de-tensions and loses its kinetic energy. The filter mat then offers sufficient resistivity to resist to the broken water jet. Thus, this measure effectively supports IP protection.

If it is provided that a mat holder is integrally fitted to the rear face of the louvered grille into which the filter mat is inserted, then functionality of the louvered grille is expanded by simple constructive measures. The mat holder fixes the filter mat with respect to the louvers in a defined manner.

A further functional extension may occur in that hinge seats are fitted to the lower face of the louvered grille. By means of those hinge seats, the louvered grille may be coupled to hinge pieces of the air filter housing, whereby a hinge axis results around which the louvered grille may be folded down. Thus, the rear face of the louvered grille and the interior of the air filter housing may be accessed for purposes of maintenance. For example, a filter mat may be replaced then. An appealing optical design results when it is provided that the hinge seats are covered by a screen extending in the widthwise direction of the louvered grille at a front face thereof.

Furthermore, it may be provided that the louvered grille comprises a handled seat into which a handle is pivotably inserted. The handle serves as a locking aid when the louvered grille is situated in its put up operating position. With the aid of the handle, the louvered grille may be unlocked and be moved into a folded down mounting position, for example via the hinge joint to the air filter housing.

The invention will be explained in detail below with the aid of an exemplary embodiment illustrated in the drawings. It is shown in:

FIG. 1 a louvered grille in a perspective front view;

FIG. 2 the louvered grille of FIG. 1 in a front view;

FIG. 3 a section along III-III illustrated in FIG. 2;

FIG. 4 a section along IV-IV illustrated in the drawings; and

FIG. 5 a partial section along V-V illustrated in FIG. 2.

FIG. 1 shows a louvered grille comprising two side parts 10 spaced apart from another. As may be recognized in FIG. 5, side parts 10 comprise a wall section perpendicular to the rear face of the louvered grille which is embodied as a mat holder 12. Convexly curved connection sections 11 merge into mat holder 12 which end as angled side walls 15. Side walls 15 in turn are parallel to mat holder 12.

As may be further recognized from FIG. 1, louvers 30 extend between side parts 10. They extend between side parts 10 in widthwise direction of the louvered grille. Louvers 30 are embodied as strip-shaped material sections extending transversely to the vertical direction of the louvered grille, i.e. inclined to a rear face of the louvered grille. Louvers 30 are coupled to connecting sections 11 via walls 13 extending vertically to the rear side of the louvered grilles at their longitudinal ends. Louvers 30 are directly coupled to connecting sections 11 at their upper edges. Air passage openings are formed between louvers 11 and side parts 10. Those air passage openings form an air guiding connection between the rear face of the louvered grille and the front face of the louvered grille. A bar 14 is formed to louvers 30 in the middle portion between the two side parts 10. That bar interconnects individual louvers 30 and thus serves for mechanical stiffening. The louvered grille is, at its upper horizontal edge, finalized by means of a transfer bar 19 having a convexly curved surface. Transverse bar 19 connects the two side parts 10. Another transverse bar 18.2 is arranged at the lower horizontal edge of the louvered grille, also interconnecting both side bars 10. Transverse bar 18.2 comprises a screen 18.1 optically covering hinge seats 16 to the front face of the louvered grille. A terminal wall 17 is formed at screen 18.1 which is perpendicular to the rear face of the louvered grille. At the upper edge region, a handle seat 20 is formed into the louvered grille into which a handle 21 may be snapped in, wherein handle 21 may be pivoted around a horizontal pivot axis with respect to the louvered grille between a locking position and an unlocking position. Handle 21 comprises a manipulator 22 which is accessible via a handle recess 23. Handle 21 may be gripped at manipulator 22 and can be unlocked.

In FIG. 2, the louvered grille is illustrated without handle 21, so that handle seat 20 may be clearly recognized.

FIG. 3 shows a section along III-III illustrated in FIG. 2. As apparent from this illustration, bar 14 connects as a stiff wall all louvers 30 and is coupled to upper and lower transverse bars 19, 18.2 at its longitudinal ends. Further, it may be recognized from this illustration that mat holder 12 is formed by four wall pieces which are vertical to the rear face of the louvered grille as a continuous frame. A filter mat, not illustrated in the drawing, may be inserted into mat holder 12. The filter mat abuts at bar 14 with its front face and is thereby kept spaced apart to the rear faces of the louvers 30.

The geometry of louvers 30 is illustrated in detail in FIG. 4. As may be recognized from this illustration, louvers 30 have an upper louver face 31 and a lower louver face 32. A barrier wall 33 is formed to the upper horizontal edge of louvers 30, which barrier wall is vertical to the rear face of the louvered grille and extends towards the rear face of the louvered grille. Air passage openings are formed between the individual louvers 30. As further illustrated in FIG. 4, both the upper louver side 31 and the lower louver side 32 are curved. Thereby, upper louver side 31 has a convex curvature and lower louver face 32 has a concave curvature. Upper louver face 31 has a concave curvature extending in the vertical direction of the louvered grille with a transverse radius R₃, as illustrated in FIG. 4. Lower louver face 32 has a concave curvature also extending in the vertical direction of the louvered grille. In addition to these convex curvatures of lower louver face 31 extending in the vertical direction of the louvered grille, upper louver faces comprise a further convexity. This convexity extends in widthwise direction of the louvered grille, as may be seen in FIG. 5. Accordingly, upper louver face 31 has a convex curvature which extends as a circular bend between side parts 10. As illustrated in FIG. 5, the upper edges of louvers 30 form a curved contour having an inner radius R₂. The lower edges of louvers 30 form a circular arc having an outer radius R₃. Having outer radius R₂ and inner radius R₁, louvers 30 are convexly curved both in widthwise direction of the louvered direction and in the vertical direction of the louvered grille, and a dual crowned vertical curvature of louvers 30 results providing for radial atomization of a vertically impinging water jet onto louver 30 and thus improves IP protection. IP protection is further improved with the aid of barrier wall 33. When a water jet of a steam cleaner is guided through the air passage openings, it directly impinges onto barrier wall 33 and is broken up. Thereby, it loses its kinetic energy and can be drained off in the direction of the gravity within the filter mat supported by mat holders 12 in a reliable manner. As can be recognized in FIG. 4 illustrating the louvered grille in its vertical operating position, the water flows in the direction of gravity and impinges onto the lower horizontal mat holder 12. An exit opening is formed between lower horizontal louver 30 and convexly curved transverse bar 18.2 through which draining water is discharged via screen 18.1 to the outer face of the louvered grille. As can be recognized in FIG. 4, to improve the look, transverse bar 18.2 is in its exterior view adapted to the design of the upper louver face 31 and has an identical contour. Thus, a continuous look of louvered grille is achieved. 

1-11. (canceled)
 12. A louvered grille for air conduction housings mounted in openings of switchgear cabinets, comprising a plurality of louvers which are spaced apart from another to form air passage openings, wherein the louvers extend in the widthwise direction of the louvered grille and have an upper louver face that is directed to the exterior and inclined transversely with respect to the vertical direction of the louvered grille, wherein the upper louver face of at least some of the louvers has a convex curvature in at least some areas thereof, both in the widthwise direction of the louvered grill (outer radius (R2) or inner radius (R1), respectively) and in the vertical direction of the louvered grille (transverse radius (R3)), the louvers comprising a barrier wall at the lower louver face thereof, which barrier wall is fitted to the upper horizontal edge of the louvers and is angled with respect to the lower louver face and extends towards a rear side of the louvered grille.
 13. The louvered grille of claim 12, wherein the louvers are strip-shaped and, starting from a center portion thereof towards the longitudinal ends (vertical direction of the louvered grille), slope in the direction of gravity.
 14. The louvered grille of claim 12, wherein the louvers have, at a lower louver face facing away from the upper louver face, a concave curvature in at least some areas thereof.
 15. The louvered grille of claim 12, wherein the barrier wall, starting from the center portion of the louvered grille, has a larger dimension in direction of the depth of the louvered grille than at the longitudinal ends thereof.
 16. The louvered grille of claim 12, wherein the louvers have a curved contour at their edges extending in the widthwise direction, wherein the radii (inner radius (R1) and outer radius (R2)) of the two curved contours are different from another.
 17. The louvered grille of claim 12, wherein a filter mat is provided in the region of the rear face of the louvers which is spaced apart from the louvers.
 18. The louvered grill of claim 17, wherein a mat holder is integrally fitted to the rear face of the louvered grille, into which the filter mat is inserted.
 19. The louvered grille of claim 12, wherein hinge seats are fitted to the lower face of the louvered grille.
 20. The louvered grille of claim 19, wherein the hinge seats are covered by a screen extending in the widthwise direction of the louvered grille at a front face thereof.
 21. The louvered grille of claim 12, further comprising a handle seat into which a handle is pivotally inserted. 